/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
*/
/*
* @test
* @bug 4486658
* @summary basic safety and liveness of ReentrantLocks, and other locks based on them
* @library /lib/testlibrary/
*/
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.util.SplittableRandom;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import jdk.testlibrary.Utils;
public final class CheckedLockLoops {
static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
static ExecutorService pool;
static final SplittableRandom rnd = new SplittableRandom();
public static void main(String[] args) throws Exception {
final int maxThreads = (args.length > 0)
? Integer.parseInt(args[0])
: 5;
int iters = 3000;
pool = Executors.newCachedThreadPool();
for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) {
oneTest(i, iters / i);
}
pool.shutdown();
if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
throw new Error();
pool = null;
}
static void oneTest(int nthreads, int iters) throws Exception {
System.out.println("Threads: " + nthreads);
int v = rnd.nextInt();
System.out.print("builtin lock ");
new BuiltinLockLoop().test(v, nthreads, iters);
System.out.print("ReentrantLock ");
new ReentrantLockLoop().test(v, nthreads, iters);
System.out.print("Mutex ");
new MutexLoop().test(v, nthreads, iters);
System.out.print("ReentrantWriteLock ");
new ReentrantWriteLockLoop().test(v, nthreads, iters);
System.out.print("ReentrantReadWriteLock");
new ReentrantReadWriteLockLoop().test(v, nthreads, iters);
System.out.print("Semaphore ");
new SemaphoreLoop().test(v, nthreads, iters);
System.out.print("fair Semaphore ");
new FairSemaphoreLoop().test(v, nthreads, iters);
System.out.print("FairReentrantLock ");
new FairReentrantLockLoop().test(v, nthreads, iters);
System.out.print("FairRWriteLock ");
new FairReentrantWriteLockLoop().test(v, nthreads, iters);
System.out.print("FairRReadWriteLock ");
new FairReentrantReadWriteLockLoop().test(v, nthreads, iters);
}
abstract static class LockLoop implements Runnable {
int value;
int checkValue;
int iters;
volatile int result;
final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
CyclicBarrier barrier;
final int setValue(int v) {
checkValue = v ^ 0x55555555;
value = v;
return v;
}
final int getValue() {
int v = value;
if (checkValue != ~(v ^ 0xAAAAAAAA))
throw new Error("lock protection failure");
return v;
}
final void test(int initialValue, int nthreads, int iters) throws Exception {
setValue(initialValue);
this.iters = iters;
barrier = new CyclicBarrier(nthreads+1, timer);
for (int i = 0; i < nthreads; ++i)
pool.execute(this);
barrier.await();
barrier.await();
long time = timer.getTime();
long tpi = time / (iters * nthreads);
System.out.print("\t" + LoopHelpers.rightJustify(tpi) + " ns per update");
// double secs = (double)(time) / 1000000000.0;
// System.out.print("\t " + secs + "s run time");
System.out.println();
if (result == 0) // avoid overoptimization
System.out.println("useless result: " + result);
}
abstract int loop(int n);
public final void run() {
try {
barrier.await();
result += loop(iters);
barrier.await();
}
catch (Exception ie) {
return;
}
}
}
private static class BuiltinLockLoop extends LockLoop {
final int loop(int n) {
int sum = 0;
int x = 0;
while (n-- > 0) {
synchronized (this) {
x = setValue(LoopHelpers.compute1(getValue()));
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantLockLoop extends LockLoop {
private final ReentrantLock lock = new ReentrantLock();
final int loop(int n) {
final ReentrantLock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class MutexLoop extends LockLoop {
private final Mutex lock = new Mutex();
final int loop(int n) {
final Mutex lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairReentrantLockLoop extends LockLoop {
private final ReentrantLock lock = new ReentrantLock(true);
final int loop(int n) {
final ReentrantLock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantWriteLockLoop extends LockLoop {
private final Lock lock = new ReentrantReadWriteLock().writeLock();
final int loop(int n) {
final Lock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairReentrantWriteLockLoop extends LockLoop {
final Lock lock = new ReentrantReadWriteLock(true).writeLock();
final int loop(int n) {
final Lock lock = this.lock;
int sum = 0;
int x = 0;
while (n-- > 0) {
lock.lock();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
lock.unlock();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class SemaphoreLoop extends LockLoop {
private final Semaphore sem = new Semaphore(1, false);
final int loop(int n) {
final Semaphore sem = this.sem;
int sum = 0;
int x = 0;
while (n-- > 0) {
sem.acquireUninterruptibly();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
sem.release();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class FairSemaphoreLoop extends LockLoop {
private final Semaphore sem = new Semaphore(1, true);
final int loop(int n) {
final Semaphore sem = this.sem;
int sum = 0;
int x = 0;
while (n-- > 0) {
sem.acquireUninterruptibly();
try {
x = setValue(LoopHelpers.compute1(getValue()));
}
finally {
sem.release();
}
sum += LoopHelpers.compute2(x);
}
return sum;
}
}
private static class ReentrantReadWriteLockLoop extends LockLoop {
private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
final int loop(int n) {
final Lock rlock = lock.readLock();
final Lock wlock = lock.writeLock();
int sum = 0;
int x = 0;
while (n-- > 0) {
if ((n & 16) != 0) {
rlock.lock();
try {
x = LoopHelpers.compute1(getValue());
x = LoopHelpers.compute2(x);
}
finally {
rlock.unlock();
}
}
else {
wlock.lock();
try {
setValue(x);
}
finally {
wlock.unlock();
}
sum += LoopHelpers.compute2(x);
}
}
return sum;
}
}
private static class FairReentrantReadWriteLockLoop extends LockLoop {
private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
final int loop(int n) {
final Lock rlock = lock.readLock();
final Lock wlock = lock.writeLock();
int sum = 0;
int x = 0;
while (n-- > 0) {
if ((n & 16) != 0) {
rlock.lock();
try {
x = LoopHelpers.compute1(getValue());
x = LoopHelpers.compute2(x);
}
finally {
rlock.unlock();
}
}
else {
wlock.lock();
try {
setValue(x);
}
finally {
wlock.unlock();
}
sum += LoopHelpers.compute2(x);
}
}
return sum;
}
}
}